my gsm sim900 module is not responding to AT commands ...

[puneethalbert]

my gsm sim900 module is not responding to "AT"commands i tried in putty and even in hyperterminals software but its nt resonding,but if put sim and call it,i ll get a ringing tone ,i dont knw whether sim900 mudule problm or any software problem?....anyone help me ,y am not getting "ok" response from the sim900......

 

[ADGAN]

Do you getting an error when you type "AT" ?

 

[puneethalbert]

No am not getting any error Msg's also...if I type "AT " in Putty software it ll remain in that line only...it won't show "ok" in response,no response at al,not even error msg.....what's the problem I don't knw....

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But if I call to that number it ll ring,I tried to send commands from Rx and Tx pin of arduino also,even it dint respond.....plz anyone help me I hav to submit my project next week...

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Now am not getting ringing tone also ,wen I call to that Sim in gsm module....what's the problem?

 

[puneethalbert]

No am not getting any error Msg's also...if I type "AT " in Putty software it ll remain in that line only...it won't show "ok" in response,no response at al,not even error msg.....what's the problem I don't knw....

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But if I call to that number it ll ring,I tried to send commands from Rx and Tx pin of arduino also,even it dint respond.....plz anyone help me I hav to submit my project next week...

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Now am not getting ringing tone also ,wen I call to that Sim in gsm module....what's the problem?

now am getting ringing tone ,but am not getting any response from gsm sim900 module,plz anyone help me,whats the problem?

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anyone help me plz.....y am not getting any response from gsm module?.....

 

[nandhu015]

Check the baud rate setting..

 

[ADGAN]

Try using the ATE0 command and check whether you are getting a reply from the modem

 

[horace1]

are the Tx and Rx lines the correct way around?
Do you have access to an oscilloscope - if so have a look at the signals on the Tx and Rx lines? you can also check the baudrate

 

[HammadLakhani]

I have recently suffered from the same issue.. but my modem was TC35i of sainsmart. I changed the modem 2 times because of this issue due to lack of time. Your may check PC to modem COM port, equal Baud rates and other parameters such as stop bit flow control none, Use hyperterminal. Ask anything i am here doing a similar project currently.

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yes you can check by checking the voltages on TX pin and RX pin. it should be one in + around 10 something and the other should be less than 0 around the number.